There is a need to ascertain the uncertainty of measurement data obtained by analyzers. For example, Japanese Laid-Open Patent Publication No. 2004-20323 discloses a measuring device that calculates the composite uncertainty by combining the uncertainty of the allowable margin of error of devices of the measurement unit, the uncertainty of device operation, the uncertainty of the calibration curve when measuring a standard sample, and the uncertainty of the measurement values of unknown samples when such unknown samples are measured.
Quality control systems are known which collect the measurement data of quality control substances using a network, and perform quality control based on collected measurement data (for example, U.S. Pat. No. 6,937,964). This quality control system is capable of comparing measurement data of quality control substances from analyzers at the same facility, and measurement data of quality control substances from analyzers at other facilities. Therefore, an operator of an analyzer connected to this quality control system compares the measurement data from the same facility with average values or the like of measurement data from other facilities, and determines that a sample can be measured by the analyzer when the collected measurement data are within an allowed range.
Japanese Laid-Open Patent Publication No. 2004-20323 does not disclose, however, a method for evaluating a measurement apparatus by the composite uncertainty of measurement data combined by the measurement apparatus. Therefore, the operator of the analyzer can not determine whether or not a sample can be measured by the analyzer based on uncertain data even when the measurement apparatus has calculated the uncertainty of the measurement data. The measurement apparatus disclosed in Japanese Laid-Open Patent Publication No. 2004-20323 must perform multiple measurements of the same unknown sample in order to calculate the uncertainty of the measurement values of the unknown sample when an unknown sample is measured. Since samples are usually collected from a patient, however, collecting sufficient unknown sample from a patient for several measurements places a burden on the patient.
Furthermore, although the quality control system disclosed in U.S. Pat. No. 6,937,964 is extremely useful, including uncertainty in the measurement data was not considered.